scripts: runner: core: fix comment typo

    tool-specific environment variables to control runner behavior.

    To support a transition to ZephyrBinaryRunner and subclasses, this

    class provides a create_for_shell_script() static factory method.

    This method iterates over ZephyrBinaryRUnner subclasses,

    This method iterates over ZephyrBinaryRunner subclasses,

    determines which (if any) can provide equivalent functionality to

    the shell-based runner, and returns a subclass instance with its

    configuration determined from the environment.